chore: reorganize docs apps (#7228)

* reorganize docs apps

* add README

* fix directory

* add condition for old docs

www/apps/user-guide/utils/base-path-url.ts

@@ -0,0 +1,3 @@
+export function basePathUrl(path = "") {
+  return `${process.env.NEXT_PUBLIC_BASE_PATH}${path}`
+}